Roll damping apparatus for waterborne craft



July 7, 1959 P. DU CANE 2,393,340

ROLL DAMPING APPARATUS FOR WATER-BORNE CRAFT Filed Dec. 26, 1956 3 Sheets Sheet l July 7, 1959 P. DU CANE 40.

ROLL DAMPING APPARATUS FOR WATER-BORNE CRAFT Filed Dec. 26, 1956 3 Sheets-Sheet 2 July 7,1959 I PL DU CANE 2,893,340

ROLL. DAMPING APPARATUS FOR WATER-BORNE CRAFT Filed necize, 195s 5 Sheets-Sheet s United rates Patent M ROLL DAMPIN G APPARATUS FOR WATER- BORNE CRAFT Peter Du Cane, Northampton, England, assignor to Vosper Limited, Portsmouth, England Application December 26, 1956, Serial No. 630,550

Claims priority, application Great Britain December 30, 1955 2 Claims. (Cl. 114126) This invention relates to roll damping suitable for small water-borne craft.

With small craft there is not usually the space for retracting stabilizing fins into the craft and therefore in the event of a breakdown in the operating gear danger might might arise from an uncontrolled fin.

The present invention consists of a stabilizing fin installation suitable for small Water-borne craft in which means are provided for braking the fin.

Preferably the fin is arranged to be braked to a member which can be rotated manually or otherwise about the fin axis of rotation whereby the fin can be moved to an innocuous position in the event of breakdown of the operating gear.

Conveniently, means are provided for locking the fin in the position to which it has been rotated.

One or more locking positions may be provided. Thus in addition to the innocuous position for when the craft is moving in the water a second locking position can be provided in which the fins are located edge on to a mudbank on which the craft may be beached so that the fins sink into the mud and do not interfere with the beaching of the craft or get damaged.

The invention will be further described with reference to the accompanying drawings.

Figure 1 is a plan of an embodiment showing hydraulic arrangements for operating the fin shaft and braking and manual rotatable means according to the invention.

Figure 2 is an end elevation of the embodiment.

Figure 3 is a section on the line AA of Figure 1, and

Figure 4 is a section on the line BB of Figure 3.

The installation comprises a baseplate 1 on which are mounted a bearing 2 for the stabilizing fin shaft 3 and two hydraulic cylinders 4 for operating the fin shaft by pivotal engagement with respective lugs 5a on a brake drum 5 keyed to the fin shaft by a key 5b.

Within the drum is provided two pivotally mounted brake shoes 6 and brake-shoe-operating arrangements of normal construction, comprising an hydraulic cylinder 6a supplied from an hydraulic connection 6b and restoring springs 60, such as are used for vehicle brakes,

2,893,340 Patented July 7, 1959 The shoes 6 are locked to an assembly comprising an inner member 7 and carrier plate 7a, which assembly is adapted to rotated on the drum about the fin shaft axis and is formed with a toothed quadrant 8 which engages with a wormwheel 9 rotatably mounted on the baseplate 1 and which may be operated from either end by means of a loose handle (not shown) adapted to fit over the squared ends.

Holes 10a are provided in lugs 10 on the drum for a locking pin 11.

The lugs lie on either side of a locking plate 12 on the baseplate 1, also provided with holes 12a so that the pin 11 can be passed through the three holes in certain positions to lock the fin against rotation.

In operation, should for any reason the coupling 14 between one or both of the hydraulic cylinders and the drum 5 be broken, then the fin can be turned manually, for example, by means of the worm gear after engagement of the brake shoe 6 with the brake drum, and then locked in the desired position by means of the pin 11.

When a craft is to be placed in a mudberth, the fins are rotated from their normal fore and aft plane, through into the vertical plane, with their leading edges downwards, so that the vessel sits vertically downwards into the mudberth, the edge-on aspect of the fin is presented and risk of strain or damage is thereby reduced to a minimum.

For the mud-bank position of the fins the quadrant 8 needs to extend round and an additional plate 12a with holes provided on the drum for engagement with lugs by the locking pin 11.

I claim:

1. In a stabilising fin installation the combination which consists of a fin shaft, supporting and bearing means for the shaft, means mounted on the supporting means for oscillating the shaft, gear means mounted on the supporting means, brake securing means mounted for rotation around the shaft by the gear means and brake-co-operating means rotating with the shaft for engagement with the brake securing means for securing the shaft thereto and permitting its rotation by the gear means.

2. The combination as claimed in claim 1 comprising aperture means on the brake-co-operating means and on the supporting means arranged to be aligned in a particular rotational position of the brake-co-operating means and pin means for passage therethrough in the aligned position for locking the brake-co-operating means against rotation in relation to the support means.

References Cited in the file of this patent UNITED STATES PATENTS 1,475,460 Thompson et al. Nov. 27, 1923 1,891,272 Slonirnsky Dec. 20, 1932 2,274,334 Keller Feb. 24, 1942 2,705,934 Kefeli Apr. 12, 1955 

